path: root/camel/providers/mbox/camel-mbox-summary.c

/*
 *  Copyright (C) 2000 Helix Code Inc.
 *
 *  Authors: Michael Zucchi <notzed@helixcode.com>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/uio.h>

#include <stdio.h>
#include <string.h>

#include <gtk/gtk.h>

#include <camel/camel-mime-message.h>

#include <camel/camel-mime-parser.h>
#include <camel/camel-mime-filter.h>
#include <camel/camel-mime-filter-basic.h>
#include <camel/camel-mime-filter-charset.h>
#include <camel/camel-mime-filter-index.h>

#include <camel/camel-mime-utils.h>

#include "camel-mbox-summary.h"

#include <errno.h>
#include <ctype.h>
#include <netinet/in.h>

#define d(x)

#define CAMEL_MBOX_SUMMARY_VERSION 3

static int safe_write(int fd, char *buffer, size_t towrite);
static void camel_mbox_summary_add(CamelMboxSummary *s, CamelMboxMessageInfo *info);

/*
  Disk file format?

  message uid
message-block
  date:
  date received?

  subject: (unicode encoded)
  from: (unicode encoded)
  to: (unicode)

  content-block

content-block
  content-type: ; params;
  content-id:
  content-description:
  content-transfer-encoding:
  message-start:
  header-size:
  body-size:

  message-block
  multipart-block

 */

/* pah, i dont care, its almost no code and it works, dont need a glist */
struct _node {
    struct _node *next;
};

static struct _node *
my_list_append(struct _node **list, struct _node *n)
{
    struct _node *ln = (struct _node *)list;
    while (ln->next)
        ln = ln->next;
    n->next = 0;
    ln->next = n;
    return n;
}

static int
my_list_size(struct _node **list)
{
    int len = 0;
    struct _node *ln = (struct _node *)list;
    while (ln->next) {
        ln = ln->next;
        len++;
    }
    return len;
}

/* low-level io functions */
static int
encode_int (FILE *out, gint32 value)
{
    int i;

    for (i=28;i>0;i-=7) {
        if (value >= (1<<i)) {
            unsigned int c = (value>>i) & 0x7f;
            if (fputc(c, out) == -1)
                return -1;
        }
    }
    return fputc(value | 0x80, out);
}

static gint32
decode_int (FILE *in)
{
        gint32 value=0, v;

        /* until we get the last byte, keep decoding 7 bits at a time */
        while ( ((v = fgetc(in)) & 0x80) == 0 && v!=EOF) {
                value |= v;
                value <<= 7;
        }
        value |= (v&0x7f);
        return value;
}

static int
encode_fixed_int (FILE *out, gint32 value)
{
    guint32 save;

    save = htonl(value);
    return fwrite(&save, sizeof(save), 1, out);
}

static gint32
decode_fixed_int (FILE *out)
{
    guint32 save;

    if (fread(&save, sizeof(save), 1, out) != -1) {
        return ntohl(save);
    } else {
        return -1;
    }
}

/* should be sorted, for binary search */
/* This is a tokenisation mechanism for strings written to the
   summary - to save space.
   This list can have at most 31 words. */
static char * tokens[] = {
    "7bit",
    "8bit",
    "alternative",
    "application",
    "base64",
    "boundary",
    "charset",
    "filename",
    "html",
    "image",
    "iso-8859-1",
    "iso-8859-8",
    "message",
    "mixed",
    "multipart",
    "name",
    "octet-stream",
    "parallel",
    "plain",
    "quoted-printable",
    "rfc822",
    "text",
    "us-ascii",     /* 23 words */
};

#define tokens_len (sizeof(tokens)/sizeof(tokens[0]))

/* baiscally ...
    0 = null
    1-tokens_len == tokens[id-1]
    >=32 string, length = n-32
*/

static int
encode_string (FILE *out, char *str)
{
    if (str == NULL) {
        return encode_int(out, 0);
    } else {
        int len = strlen(str);
        int i, token=-1;

        if (len <= 16) {
            char lower[32];

            for (i=0;i<len;i++)
                lower[i] = tolower(str[i]);
            lower[i] = 0;
            for (i=0;i<tokens_len;i++) {
                if (!strcmp(tokens[i], lower)) {
                    token = i;
                    break;
                }
            }
        }
        if (token != -1) {
            return encode_int(out, token+1);
        } else {
            if (encode_int(out, len+32) == -1)
                return -1;
            return fwrite(str, len, 1, out);
        }
    }
    return 0;
}

static char *
decode_string (FILE *in)
{
    char *ret;
    int len;
    
    len = decode_int(in);

    if (len<32) {
        if (len <= 0) {
            ret = NULL;
        } else if (len<= tokens_len) {
            ret = g_strdup(tokens[len-1]);
        } else {
            g_warning("Invalid token encountered: %d", len);
            ret = NULL;
        }
    } else if (len > 10240) {
        g_warning("Got broken string header length: %d bytes", len);
        ret = NULL;
    } else {
        len -= 32;
        ret = g_malloc(len+1);
        if (fread(ret, len, 1, in) == -1) {
            g_free(ret);
            return NULL;
        }
        ret[len]=0;
    }

    return ret;
}



/* allocation functions */

static void
body_part_dump(CamelMboxMessageContentInfo *bs, int depth)
{
    CamelMboxMessageContentInfo *c;
    char *prefix;

    if (bs == NULL)
        return;

    prefix = alloca(depth*2+1);
    memset(prefix, ' ', depth*2);
    prefix[depth*2]=0;
    printf("%scontent-range: %d %d %d\n", prefix, (int)bs->pos, (int)bs->bodypos, (int)bs->endpos);
    printf("%scontent-type: %s/%s\n", prefix, bs->info.type?bs->info.type->type:"?", bs->info.type?bs->info.type->subtype:"?");
    printf("%scontent-id: %s\n", prefix, bs->info.id);
    printf("%scontent-description: %s\n", prefix, bs->info.description);
    printf("%scontent-transfer-encoding: %s\n", prefix, bs->info.encoding);
    c = (CamelMboxMessageContentInfo *)bs->info.childs;
    while (c) {
        printf("%s -- \n", prefix);
        body_part_dump(c, depth+1);
        c = (CamelMboxMessageContentInfo *)c->info.next;
    }
}

static void
message_struct_dump(CamelMboxMessageInfo *ms)
{
    char *tmp;

    if (ms == NULL) {
        printf("Empty message?\n");
        return;
    }

    printf("Subject: %s\n", ms->info.subject);
    printf("From: %s\n", ms->info.from);
    printf("To: %s\n", ms->info.to);
    tmp = header_format_date(ms->info.date_sent, 0);
    printf("Date: %s\n", tmp);
    g_free(tmp);
    tmp = header_format_date(ms->info.date_received, 0);
    printf("Date-Received: %s\n", tmp);
    g_free(tmp);
    printf("UID: %08x-%04x\n", atoi(ms->info.uid), ms->info.flags);
    printf(" -- content ->\n");
    body_part_dump((CamelMboxMessageContentInfo *)ms->info.content, 1);
}

static CamelMboxMessageContentInfo *
body_part_new(CamelMimeParser *mp, CamelMboxMessageContentInfo *parent, int start, int body)
{
    CamelMboxMessageContentInfo *bs;

    bs = g_malloc0(sizeof(*bs));

    bs->info.parent = (CamelMessageContentInfo *)parent;

    bs->info.type = camel_mime_parser_content_type(mp);
    header_content_type_ref(bs->info.type);

    bs->info.id = header_msgid_decode(camel_mime_parser_header(mp, "content-id", NULL));
    bs->info.description = header_decode_string(camel_mime_parser_header(mp, "content-description", NULL));
    bs->info.encoding = header_content_encoding_decode(camel_mime_parser_header(mp, "content-transfer-encoding", NULL));

    /* not sure what to set here? */
    bs->pos = start;
    bs->bodypos = body;
    bs->endpos = -1;

    if (parent)
        my_list_append((struct _node **)&parent->info.childs, (struct _node *)bs);

    return bs;
}

static CamelMboxMessageInfo *
message_struct_new(CamelMimeParser *mp, CamelMboxMessageContentInfo *parent, int start, int body, off_t xev_offset)
{
    CamelMboxMessageInfo *ms;
    struct _header_address *addr;
    const char *text;

    ms = g_malloc0(sizeof(*ms));

    /* FIXME: what about cc, sender vs from? */
    ms->info.subject = header_decode_string(camel_mime_parser_header(mp, "subject", NULL));
    text = camel_mime_parser_header(mp, "from", NULL);
    addr = header_address_decode(text);
    if (addr) {
        ms->info.from = header_address_list_format(addr);
        header_address_list_clear(&addr);
    } else {
        ms->info.from = g_strdup(text);
    }
    text = camel_mime_parser_header(mp, "to", NULL);
    addr = header_address_decode(text);
    if (addr) {
        ms->info.to = header_address_list_format(addr);
        header_address_list_clear(&addr);
    } else {
        ms->info.to = g_strdup(text);
    }

    ms->info.date_sent = header_decode_date(camel_mime_parser_header(mp, "date", NULL), NULL);
    ms->info.date_received = 0;

    ms->info.content = (CamelMessageContentInfo *)body_part_new(mp, parent, start, body);
    ms->xev_offset = xev_offset;

    return ms;
}

static void
body_part_free(CamelMboxMessageContentInfo *bs)
{
    CamelMboxMessageContentInfo *c, *cn;

    c = (CamelMboxMessageContentInfo *)bs->info.childs;
    while (c) {
        cn = (CamelMboxMessageContentInfo *)c->info.next;
        body_part_free(c);
        c = cn;
    }
    g_free(bs->info.id);
    g_free(bs->info.description);
    g_free(bs->info.encoding);
    header_content_type_unref(bs->info.type);
    g_free(bs);
}

static void
message_struct_free(CamelMboxMessageInfo *ms)
{
    g_free(ms->info.subject);
    g_free(ms->info.to);
    g_free(ms->info.from);
    body_part_free((CamelMboxMessageContentInfo *)ms->info.content);
    g_free(ms);
}


/* IO functions */
static CamelMboxMessageContentInfo *
body_part_load(FILE *in)
{
    CamelMboxMessageContentInfo *bs = NULL, *c;
    struct _header_content_type *ct;
    char *type;
    char *subtype;
    int i, count;

    d(printf("got content-block\n"));
    bs = g_malloc0(sizeof(*bs));
    bs->pos = decode_int(in);
    bs->bodypos = bs->pos + decode_int(in);
    bs->endpos = bs->pos + decode_int(in);

    /* do content type */
    d(printf("got content-type\n"));
    type = decode_string(in);
    subtype = decode_string(in);

    ct = header_content_type_new(type, subtype);
    bs->info.type = ct;
    count = decode_int(in);
    d(printf("getting %d params\n", count));
    for (i=0;i<count;i++) {
        char *name = decode_string(in);
        char *value = decode_string(in);
        
        d(printf(" %s = \"%s\"\n", name, value));
        
        header_content_type_set_param(ct, name, value);
        /* FIXME: do this so we dont have to double alloc/free */
        g_free(name);
        g_free(value);
    }

    d(printf("got content-id\n"));
    bs->info.id = decode_string(in);
    d(printf("got content-description\n"));
    bs->info.description = decode_string(in);
    d(printf("got content-encoding\n"));
    bs->info.encoding = decode_string(in);

    count = decode_int(in);
    d(printf("got children, %d\n", count));
    for (i=0;i<count;i++) {
        c = body_part_load(in);
        if (c) {
            my_list_append((struct _node **)&bs->info.childs, (struct _node *)c);
            c->info.parent = (CamelMessageContentInfo *)bs;
        } else {
            printf("Cannot load child\n");
        }
    }

    return bs;
}

static int
body_part_save(FILE *out, CamelMboxMessageContentInfo *bs)
{
    CamelMboxMessageContentInfo *c, *cn;
    struct _header_content_type *ct;
    struct _header_param *hp;

    encode_int(out, bs->pos);
    encode_int(out, bs->bodypos - bs->pos);
    encode_int(out, bs->endpos - bs->pos);

    ct = bs->info.type;
    if (ct) {
        encode_string(out, ct->type);
        encode_string(out, ct->subtype);
        encode_int(out, my_list_size((struct _node **)&ct->params));
        hp = ct->params;
        while (hp) {
            encode_string(out, hp->name);
            encode_string(out, hp->value);
            hp = hp->next;
        }
    } else {
        encode_string(out, NULL);
        encode_string(out, NULL);
        encode_int(out, 0);
    }
    encode_string(out, bs->info.id);
    encode_string(out, bs->info.description);
    encode_string(out, bs->info.encoding);

    encode_int(out, my_list_size((struct _node **)&bs->info.childs));

    c = (CamelMboxMessageContentInfo *)bs->info.childs;
    while (c) {
        cn = (CamelMboxMessageContentInfo *)c->info.next;
        body_part_save(out, c);
        c = cn;
    }

    return 0;
}

static CamelMboxMessageInfo *
message_struct_load(FILE *in)
{
    CamelMboxMessageInfo *ms;

    ms = g_malloc0(sizeof(*ms));

    ms->info.uid = g_strdup_printf("%u", decode_int(in));
    ms->info.flags = decode_int(in);
    ms->info.date_sent = decode_int(in);
    ms->info.date_received = decode_int(in);
    ms->xev_offset = decode_int(in);
    ms->info.subject = decode_string(in);
    ms->info.from = decode_string(in);
    ms->info.to = decode_string(in);
    ms->info.content = (CamelMessageContentInfo *)body_part_load(in);

    return ms;
}

static int
message_struct_save(FILE *out, CamelMboxMessageInfo *ms)
{
    encode_int(out, strtoul(ms->info.uid, NULL, 10));
    encode_int(out, ms->info.flags);
    encode_int(out, ms->info.date_sent);
    encode_int(out, ms->info.date_received);
    encode_int(out, ms->xev_offset);
    encode_string(out, ms->info.subject);
    encode_string(out, ms->info.from);
    encode_string(out, ms->info.to);
    body_part_save(out, (CamelMboxMessageContentInfo *)ms->info.content);

    return 0;
}

static unsigned int
header_evolution_decode(const char *in, unsigned int *uid, unsigned int *flags)
{
    char *header;
    if (in
        && (header = header_token_decode(in))) {
        if (strlen(header) == strlen("00000000-0000")
            && sscanf(header, "%08x-%04x", uid, flags) == 2) {
            g_free(header);
            return *uid;
        }
        g_free(header);
    }

    return ~0;
}

static int
safe_write(int fd, char *buffer, size_t towrite)
{
    size_t donelen;
    size_t len;

    donelen = 0;
    while (donelen < towrite) {
        len = write(fd, buffer + donelen, towrite - donelen);
        if (len == -1) {
            if (errno == EINTR || errno == EAGAIN)
                continue;
            return -1;
        }
        donelen += len;
    }
    return donelen;
}

static int
header_write(int fd, struct _header_raw *header, unsigned int uid, unsigned int flags)
{
    struct iovec iv[4];
    int outlen = 0;

    iv[1].iov_base = ":";
    iv[1].iov_len = 1;
    iv[3].iov_base = "\n";
    iv[3].iov_len = 1;

    while (header) {
        if (strcasecmp(header->name, "x-evolution")) {
            int len;

            iv[0].iov_base = header->name;
            iv[0].iov_len = strlen(header->name);
            iv[2].iov_base = header->value;
            iv[2].iov_len = strlen(header->value);

            do {
                len = writev(fd, iv, 4);
            } while (len == -1 && errno == EINTR);

            if (len == -1)
                return -1;
            outlen += len;
        }
        header = header->next;
    }

    return outlen;
}

/* returns -1 on error, else number of bytes written */
int
camel_mbox_summary_copy_block(int fromfd, int tofd, off_t readpos, size_t bytes)
{
    char buffer[4096];
    int written = 0;
    off_t pos, newpos;

    pos = lseek(fromfd, 0, SEEK_CUR);
    if (pos == -1)
        return -1;

    newpos = lseek(fromfd, readpos, SEEK_SET);
    if (newpos == -1 || newpos != readpos)
        goto error;

    d(printf("oldpos = %d;  copying %d from %d\n", (int)pos, (int)bytes, (int)readpos));

    while (bytes>0) {
        int toread, towrite, donelen;

        toread = bytes;
        if (bytes>4096)
            toread = 4096;
        else
            toread = bytes;
    reread:
        towrite = read(fromfd, buffer, toread);
        if (towrite == -1) {
            if (errno == EINTR || errno == EAGAIN)
                goto reread;
            goto error;
        }

        /* check for 'end of file' */
        if (towrite == 0)
            break;

        if ( (donelen = safe_write(tofd, buffer, towrite)) == -1)
            goto error;

        written += donelen;
        bytes -= donelen;
    }

    d(printf("written %d bytes\n", written));

    newpos = lseek(fromfd, pos, SEEK_SET);
    if (newpos == -1 || newpos != pos);
        return -1;

    return written;

error:
    lseek(fromfd, pos, SEEK_SET);
    return -1;
}

#define SAVEIT

/* TODO: Allow to sync with current summary info, without over-writing flags if they
   already exist there */
/* TODO: Lazy sync, make this read-only, and dont write out xev headers unless we need
   to? */
static int index_folder(CamelMboxSummary *s, int startoffset)
{
    CamelMimeParser *mp;
    int fd;
    int fdout;
    int state;

    int toplevel = FALSE;
    const char *xev;
    char *data;
    int datalen;

    int enc_id=-1;
    int chr_id=-1;
    int idx_id=-1;
    struct _header_content_type *ct;
    int doindex=FALSE;
    CamelMimeFilterCharset *mfc = NULL;
    CamelMimeFilterIndex *mfi = NULL;
    CamelMimeFilterBasic *mf64 = NULL, *mfqp = NULL;

    CamelMboxMessageContentInfo *body = NULL, *parent = NULL;
    CamelMboxMessageInfo *message = NULL;

    int from_end = 0;   /* start of message */
    int from = 0;       /* start of headers */
    int last_write = 0; /* last written position */
    int eof;
    int write_offset = 0;   /* how much does the dest differ from the source pos */
    int old_offset = 0;

    guint32 newuid, newflags;
    off_t xevoffset = -1;

    char *tmpname;

    printf("indexing %s (%s) from %d\n", s->folder_path, s->summary_path, startoffset);

    fd = open(s->folder_path, O_RDONLY);
    if (fd==-1) {
        perror("Can't open folder");
        return -1;
    }

    tmpname = g_strdup_printf("%s.tmp", s->folder_path);

    fdout = open(tmpname, O_WRONLY|O_CREAT|O_TRUNC, 0600);
    if (fdout==-1) {
        perror("Can't open output");
        g_free(tmpname);
        return -1;
    }

    mp = camel_mime_parser_new();
    camel_mime_parser_init_with_fd(mp, fd);
    camel_mime_parser_scan_from(mp, TRUE);

    /* FIXME: cleaner fail code */
    if (startoffset > 0) {
        if (camel_mime_parser_seek(mp, startoffset, SEEK_SET) != startoffset) {
            g_free(tmpname);
            gtk_object_unref((GtkObject *)mp);
            return -1;
        }
    }

    mfi = camel_mime_filter_index_new_ibex(s->index);

    while ( (state = camel_mime_parser_step(mp, &data, &datalen)) != HSCAN_EOF ) {
        switch(state) {
        case HSCAN_FROM: /* starting a new message content */
            /* save the current position */
            d(printf("from = %d\n", (int)camel_mime_parser_tell(mp)));
            toplevel = FALSE;
            from = camel_mime_parser_tell(mp);
            break;

        case HSCAN_FROM_END:
            d(printf("from-end = %d\n", (int)camel_mime_parser_tell(mp)));
            d(printf("message from %d to %d\n", from_end, (int)camel_mime_parser_tell(mp)));
            from_end = camel_mime_parser_tell(mp);
            break;

        case HSCAN_MESSAGE:
        case HSCAN_MULTIPART:
        case HSCAN_HEADER: /* starting a new header */
            newuid=~0;
            newflags=0;
            if (!toplevel) {
                char name[32];
                unsigned int olduid, oldflags;
                int headerlen;
                int docopy = FALSE;

                /* check for X-Evolution header ... if its there, nothing to do (skip content) */
                xev = camel_mime_parser_header(mp, "x-evolution", (int *)&xevoffset);
                if (xev) {
                    d(printf("An x-evolution header exists at: %d = %s\n", xevoffset + write_offset, xev));
                    xevoffset = xevoffset + write_offset;
                    if (header_evolution_decode(xev, &olduid, &oldflags) != ~0) {
                        d(printf(" uid = %d = %x\n", olduid, olduid));
                        newuid = olduid;
                        newflags = oldflags;
#if 0
                        while (camel_mime_parser_step(mp, &data, &datalen) != HSCAN_FROM_END)
                            ;
                        break;
#endif
                    } else {
                        printf("Invalid xev header?  I need to write out a new one ...\n");
                    }
                }

                toplevel = TRUE;

                /* assign a new uid for this message */
                if (newuid == ~0) {
                    newuid = s->nextuid++;
                    docopy = TRUE;
                } else {
                    /* make sure we account for this uid when assigning uid's */
                    /* this really needs a pre-scan pass ... *sigh* */
                    camel_mbox_summary_set_uid(s, newuid);
                }

                /* setup index name for this uid */
                sprintf(name, "%u", newuid);
                camel_mime_filter_index_set_name(mfi, name);
                /* remove all references to this name from the index */
                if (s->index)
                    ibex_unindex(s->index, name);

                d(printf("Message content starts at %d\n", camel_mime_parser_tell(mp)));
                
                if (docopy) {
                    /* now, copy over bits of mbox from last write, and insert the X-Evolution header (at the top of headers) */
                    /* if we already have a valid x-evolution header, use that, dont need to copy */
                    camel_mbox_summary_copy_block(fd, fdout, last_write, from-last_write);
                    last_write = from;

                    headerlen = header_write(fdout, camel_mime_parser_headers_raw(mp), newuid, 0);
                    sprintf(name, "X-Evolution: %08x-%04x\n\n", newuid, 0);
                    safe_write(fdout, name, strlen(name));
                    d(printf("new X-Evolution at %d\n", headerlen + from + write_offset));
                    xevoffset = headerlen + from + write_offset;
                    old_offset = write_offset;

                    write_offset += (headerlen - (camel_mime_parser_tell(mp)-from)) + strlen(name);
                    last_write = camel_mime_parser_tell(mp);
                }
            } else {
                old_offset = write_offset;
            }

            /* we only care about the rest for actual content parts */
            /* TODO: Cleanup, this is a huge mess */
            if (state != HSCAN_HEADER) {
                if (message == NULL) {
                    message = message_struct_new(mp, parent, camel_mime_parser_tell_start_headers(mp)+old_offset, camel_mime_parser_tell(mp)+write_offset, xevoffset);
                    parent = (CamelMboxMessageContentInfo *)message->info.content;
                    if (newuid != ~0) {
                        message->info.uid = g_strdup_printf("%u", newuid);
                        message->info.flags = newflags;
                    } else {
                        g_warning("This shouldn't happen?");
                    }
                } else {
                    parent = body_part_new(mp, parent, camel_mime_parser_tell_start_headers(mp)+old_offset, camel_mime_parser_tell(mp)+write_offset);
                }
                break;
            }

            if (message == NULL) {
                message = message_struct_new(mp, parent, camel_mime_parser_tell_start_headers(mp)+old_offset, camel_mime_parser_tell(mp)+write_offset, xevoffset);
                body = (CamelMboxMessageContentInfo *)message->info.content;
                if (newuid != ~0) {
                    message->info.uid = g_strdup_printf("%u", newuid);
                    message->info.flags = newflags;
                } else {
                    g_warning("This shouldn't happen?");
                }
            } else {
                body = body_part_new(mp, parent, camel_mime_parser_tell_start_headers(mp)+old_offset, camel_mime_parser_tell(mp)+write_offset);
            }

            /* check headers for types that we can index */
            ct = camel_mime_parser_content_type(mp);
            if (header_content_type_is(ct, "text", "*")) {
                char *encoding;
                const char *charset;
                
                /* TODO: The filters should all be cached, so they aren't recreated between
                   messages/message parts */
                encoding = header_content_encoding_decode(camel_mime_parser_header(mp, "content-transfer-encoding", NULL));
                if (encoding) {
                    if (!strcasecmp(encoding, "base64")) {
                        d(printf("Adding decoding filter for base64\n"));
                        if (mf64 == NULL)
                            mf64 = camel_mime_filter_basic_new_type(CAMEL_MIME_FILTER_BASIC_BASE64_DEC);
                        enc_id = camel_mime_parser_filter_add(mp, (CamelMimeFilter *)mf64);
                    } else if (!strcasecmp(encoding, "quoted-printable")) {
                        d(printf("Adding decoding filter for quoted-printable\n"));
                        if (mfqp == NULL)
                            mfqp = camel_mime_filter_basic_new_type(CAMEL_MIME_FILTER_BASIC_QP_DEC);
                        enc_id = camel_mime_parser_filter_add(mp, (CamelMimeFilter *)mfqp);
                    }
                    g_free(encoding);
                }
                
                charset = header_content_type_param(ct, "charset");
                if (charset!=NULL
                    && !(strcasecmp(charset, "us-ascii")==0
                    || strcasecmp(charset, "utf-8")==0)) {
                    d(printf("Adding conversion filter from %s to utf-8\n", charset));
                    if (mfc == NULL)
                        mfc = camel_mime_filter_charset_new_convert(charset, "utf-8");
                    if (mfc) {
                        chr_id = camel_mime_parser_filter_add(mp, (CamelMimeFilter *)mfc);
                    } else {
                        g_warning("Cannot convert '%s' to 'utf-8', message display may be corrupt", charset);
                    }
                }

                doindex = TRUE;

                /* and this filter actually does the indexing */
                idx_id = camel_mime_parser_filter_add(mp, (CamelMimeFilter *)mfi);
            } else {
                doindex = FALSE;
            }
            break;

            /* fixme, this needs thought *sigh* */
        case HSCAN_MESSAGE_END:
        case HSCAN_MULTIPART_END:
            if (parent) {
                parent->endpos = camel_mime_parser_tell(mp)+write_offset;
                if (parent->info.parent == NULL) {
                    camel_mbox_summary_add(s, message);
                    message = NULL;
                    parent = NULL;
                } else {
                    parent = (CamelMboxMessageContentInfo *)parent->info.parent;
                }
            }
            break;

        case HSCAN_BODY:
            if (doindex) {
                d(printf("Got content to index:\n%.*s", datalen, data));
            }
            break;

        case HSCAN_BODY_END:
            if (body) {
                body->endpos = camel_mime_parser_tell(mp)+write_offset;
                if (body->info.parent == NULL) {
                    camel_mbox_summary_add(s, message);
                    message = NULL;
                }
            }

            d(printf("end of content, removing decoders\n"));
            if (enc_id != -1) {
                camel_mime_parser_filter_remove(mp, enc_id);
                enc_id = -1;
            }
            if (chr_id != -1) {
                camel_mime_parser_filter_remove(mp, chr_id);
                chr_id = -1;
            }
            if (idx_id != -1) {
                camel_mime_parser_filter_remove(mp, idx_id);
                idx_id = -1;
            }
            break;
        }
    }

    /* did we actually write anything out?   Then rename and be done with it. */
    if (last_write>0) {
        eof = camel_mime_parser_tell(mp);
        camel_mbox_summary_copy_block(fd, fdout, last_write, eof-last_write);

        if (close(fdout) == -1) {
            perror("Could not close output file");
            unlink(tmpname);
        } else {
            printf("renaming %s to %s\n", tmpname, s->folder_path);
            if (rename(tmpname, s->folder_path) == -1) {
                perror("Error renaming file");
                unlink(tmpname);
            }
        }
    } else {
        /* no, then dont bother touching the inbox */
        printf("No written changes to mbox, removing tmp file\n");
        close(fdout);
        unlink(tmpname);
    }

    close(fd);

    if (mf64) gtk_object_unref((GtkObject *)mf64);
    if (mfqp) gtk_object_unref((GtkObject *)mfqp);
    if (mfc) gtk_object_unref((GtkObject *)mfc);
    if (mfi) gtk_object_unref((GtkObject *)mfi);

    /* force an index sync? */
    if (s->index) {
        ibex_write(s->index);
    }

        gtk_object_unref((GtkObject *)mp);

    /* and finally ... update the summary sync info */
    {
        struct stat st;

        if (stat(s->folder_path, &st) == 0) {
            s->time = st.st_mtime;
            s->size = st.st_size;
        }
    }

    g_free(tmpname);

    return 0;
}

CamelMboxSummary *camel_mbox_summary_new(const char *summary, const char *folder, ibex *index)
{
    CamelMboxSummary *s;

    s = g_malloc0(sizeof(*s));

    s->dirty = TRUE;
    s->folder_path = g_strdup(folder);
    s->summary_path = g_strdup(summary);
    /* FIXME: refcount index? */
    s->index = index;

    s->messages = g_ptr_array_new();
    s->message_uid = g_hash_table_new(g_str_hash, g_str_equal);

    /* always force an update */
    s->time = 0;
    s->size = 0;

    s->nextuid = 1;

    /* TODO: force an initial load right now? */

    return s;
}

void camel_mbox_summary_unref(CamelMboxSummary *s)
{
    g_warning("Unimplemented function, mbox_summary_unref");
}

/* check that the summary is uptodate, TRUE means it is uptodate */
int camel_mbox_summary_check(CamelMboxSummary *s)
{
    struct stat st;

    /* no folder at all? */
    if (stat(s->folder_path, &st) != 0)
        return FALSE;

    return (st.st_size == s->size) && (st.st_mtime == s->time);
}

static void camel_mbox_summary_add(CamelMboxSummary *s, CamelMboxMessageInfo *info)
{
    if (info->info.uid == NULL) {
        info->info.uid = g_strdup_printf("%u", s->nextuid++);
    }
    if (g_hash_table_lookup(s->message_uid, info->info.uid)) {
        g_error("Trying to insert message with clashing uid's");
    }
    d(printf("adding %s\n", info->info.uid));
    g_ptr_array_add(s->messages, info);
    g_hash_table_insert(s->message_uid, info->info.uid, info);
    s->dirty = TRUE;
}

static int summary_header_read(FILE *fp, guint32 *version, time_t *time, size_t *size, guint32 *nextuid)
{
    fseek(fp, 0, SEEK_SET);
    *version = decode_fixed_int(fp);
    *time = decode_fixed_int(fp);
    *size = decode_fixed_int(fp);
    *nextuid = decode_fixed_int(fp);
    return ferror(fp);
}

static void
summary_clear(CamelMboxSummary *s)
{
    int i;

    for (i=0;i<s->messages->len;i++) {
        message_struct_free(g_ptr_array_index(s->messages, i));
    }
    g_ptr_array_free(s->messages, TRUE);
    g_hash_table_destroy(s->message_uid);

    s->messages = g_ptr_array_new();
    s->message_uid = g_hash_table_new(g_str_hash, g_str_equal);
}

int camel_mbox_summary_load(CamelMboxSummary *s)
{
    struct stat st;
    FILE *fp;
    int i, total;
    CamelMboxMessageInfo *info;

    summary_clear(s);

    if ((fp = fopen(s->summary_path, "r")) == NULL) {
        g_warning("Loading non-existant summary, generating summary for folder: %s: %s", s->summary_path, strerror(errno));
        index_folder(s, 0);
        camel_mbox_summary_save(s);
    } else {
        guint32 version, nextuid;
        time_t time;
        size_t size;

        if (stat(s->folder_path, &st) != 0) {
            g_warning("Uh, no folder anyway, aborting");
            fclose(fp);
            return -1;
        }

        if (summary_header_read(fp, &version, &time, &size, &nextuid) != 0
            || version != CAMEL_MBOX_SUMMARY_VERSION) {
            g_warning("Summary missing or version mismatch, reloading summary");
            fclose(fp);
            index_folder(s, 0);
            camel_mbox_summary_save(s);
            return 0;
        }

        s->nextuid = MAX(s->nextuid, nextuid);
        s->time = time;
        s->size = size;
        total = decode_fixed_int(fp);
            
        if (time != st.st_mtime || size != st.st_size) {
            /* if its grown, then just index the new stuff, and load the rest from the summary */
            if (size < st.st_size) {
                g_warning("Indexing/summarizing from start position: %d", size);

                d(printf("loading %d items from summary file\n", total));
                for (i=0;i<total;i++) {
                    info = message_struct_load(fp);
                    if (info) {
                        camel_mbox_summary_add(s, info);
                    } else {
                        break;
                    }
                }
                fclose(fp);
                s->dirty = FALSE;
                index_folder(s, size); /* if it adds any, it'll dirtify it */
                camel_mbox_summary_save(s);
            } else {
                g_warning("Folder changed/smaller, reindexing everything");
                index_folder(s, 0);
                camel_mbox_summary_save(s);
                fclose(fp);
            }
            return 0;
        }

        printf("loading %d items from summary file\n", total);
        for (i=0;i<total;i++) {
            info = message_struct_load(fp);
            if (info) {
                camel_mbox_summary_add(s, info);
            } else {
                break;
            }
        }
        fclose(fp);
        s->dirty = FALSE;
    }
    return 0;
}

static int summary_header_write(FILE *fp, CamelMboxSummary *s)
{
    fseek(fp, 0, SEEK_SET);
    encode_fixed_int(fp, CAMEL_MBOX_SUMMARY_VERSION);
    encode_fixed_int(fp, s->time);
    /* if we're dirty, then dont *really* save it ... */
    if (s->dirty)
        encode_fixed_int(fp, 0);
    else
        encode_fixed_int(fp, s->size);
    encode_fixed_int(fp, s->nextuid);
    fflush(fp);
    return ferror(fp);
}

static int summary_header_save(CamelMboxSummary *s)
{
    int fd;
    FILE *fp;

    fd = open(s->summary_path, O_WRONLY|O_CREAT, 0600);
    if (fd == -1)
        return -1;
    fp = fdopen(fd, "w");
    if (fp == NULL)
        return -1;

    summary_header_write(fp, s);
    return fclose(fp);
}

int camel_mbox_summary_save(CamelMboxSummary *s)
{
    int i, fd;
    FILE *fp;

    printf("saving summary? %s\n", s->summary_path);

    /* FIXME: error checking */
    if (s->dirty) {
        printf("yes\n");
        fd = open(s->summary_path, O_WRONLY|O_CREAT|O_TRUNC, 0600);
        if (fd == -1)
            return -1;
        fp = fdopen(fd, "w");
        if (fp == NULL)
            return -1;

        s->dirty = FALSE;

        summary_header_write(fp, s);
        encode_fixed_int(fp, s->messages->len);

        printf("message count = %d\n", s->messages->len);

        for (i=0;i<s->messages->len;i++) {
            message_struct_save(fp, g_ptr_array_index(s->messages, i));
        }
        fclose(fp);
    } else {
        printf("no\n");
    }
    return 0;
}

CamelMboxMessageInfo *camel_mbox_summary_uid(CamelMboxSummary *s, const char *uid)
{
    return g_hash_table_lookup(s->message_uid, uid);
}

CamelMboxMessageInfo *camel_mbox_summary_index(CamelMboxSummary *s, int index)
{
    return g_ptr_array_index(s->messages, index);
}

int camel_mbox_summary_message_count(CamelMboxSummary *s)
{
    return s->messages->len;
}

guint32 camel_mbox_summary_next_uid(CamelMboxSummary *s)
{
    guint32 uid = s->nextuid++;

    summary_header_save(s);
    return uid;
}

guint32 camel_mbox_summary_set_uid(CamelMboxSummary *s, guint32 uid)
{
    if (s->nextuid <= uid) {
        s->nextuid = uid+1;
        summary_header_save(s);
    }
    return s->nextuid;
}

void camel_mbox_summary_set_flags_by_uid(CamelMboxSummary *s, const char *uid, guint32 flags)
{
    CamelMessageInfo *info;

    info = (CamelMessageInfo *)camel_mbox_summary_uid(s, uid);
    if (info != NULL) {
        if (info->flags != flags) {
            info->flags = flags | CAMEL_MESSAGE_FOLDER_FLAGGED;
            s->dirty = TRUE;
        }
    } else {
        g_warning("Message has dissapeared from summary?  uid %s", uid);
    }
}

/* update offsets in the summary to take account deleted parts */
static void
offset_content(CamelMboxMessageContentInfo *content, off_t offset)
{
    content->pos -= offset;
    content->bodypos -= offset;
    content->endpos -= offset;
    content = (CamelMboxMessageContentInfo *)content->info.childs;
    while (content) {
        offset_content(content, offset);
        content = (CamelMboxMessageContentInfo *)content->info.next;
    }
}

void camel_mbox_summary_remove_uid(CamelMboxSummary *s, const char *uid)
{
    CamelMboxMessageInfo *oldinfo;
    char *olduid;

    if (g_hash_table_lookup_extended(s->message_uid, uid, (void *)&olduid, (void *)&oldinfo)) {
#if 0
        /* FIXME: this code should be executed to update the summary info,
           however, only if we're not depending on the info not changing yet */
        off_t offset = info->endpos - info->pos;
        int i, count, got = FALSE;

        count = s->messages->len;
        for (i=0;i<count;i++) {
            CamelMboxMessageInfo *minfo = g_ptr_array_index(s->messages, i);
            if (got) {
                offset_content(minfo, offset);
            } else if (minfo == info) {
                got = TRUE;
            }
        }
#endif
        g_hash_table_remove(s->message_uid, uid);
        g_ptr_array_remove(s->messages, oldinfo);
        message_struct_free(oldinfo);
        g_free(olduid);
    }
}

/* perform expunge/update xev headers, etc */
/* TODO: merge this with the indexing code, so that it can index new parts
   without having to reread everything again? */
/* TODO: sync with the mbox, if it has changed */
int
camel_mbox_summary_expunge(CamelMboxSummary *s)
{
    int quick = TRUE, work=FALSE;
    int i, count;
    CamelMboxMessageInfo *info;

    printf("Executing expunge ...\n");

    count = camel_mbox_summary_message_count(s);
    for (i=0;quick && i<count;i++) {
        info = camel_mbox_summary_index(s, i);
        if (info->xev_offset == -1 || info->info.flags & CAMEL_MESSAGE_DELETED)
            quick = FALSE;
        else
            work |= (info->info.flags & CAMEL_MESSAGE_FOLDER_FLAGGED) != 0;
    }
    if (quick) {
        int fd;
        char name[32];

        if (!work)
            return 0;

        camel_mbox_summary_save(s);

        fd = open(s->folder_path, O_WRONLY);

        if (fd == -1) {
            g_error("Cannot open folder for update: %s", strerror(errno));
            return -1;
        }

        /* poke in the new xev info */
        for (i=0;i<count;i++) {
            info = camel_mbox_summary_index(s, i);
            g_assert(info);
            g_assert(info->xev_offset != -1);
            if (info->info.flags & CAMEL_MESSAGE_FOLDER_FLAGGED) {
                printf("Setting new flags to message %s = %04x\n", info->info.uid, info->info.flags & 0xffff);
                lseek(fd, info->xev_offset, SEEK_SET);
                sprintf(name, "X-Evolution: %08x-%04x\n\n", (unsigned int)strtoul(info->info.uid, NULL, 10), info->info.flags & 0xffff);
                write(fd, name, strlen(name));
                info->info.flags &= ~CAMEL_MESSAGE_FOLDER_FLAGGED;
            }
        }
        close(fd);
    } else {
        char *tmpname;
        int fd, fdout;
        int last_write = 0, offset = 0, summary_end = 0, last_start = 0;
        CamelMboxMessageContentInfo *content;
        struct stat st;

        printf("We must expunge messages and/or write headers\n");

        /* FIXME: This should check the current summary is correct */

        /* we have to write out new headers or delete messages, starting from message i */

        fd = open(s->folder_path, O_RDONLY);
        if (fd == -1) {
            g_error("Cannot open folder for read: %s", strerror(errno));
            return -1;
        }

        tmpname = g_strdup_printf("%s.tmp", s->folder_path);
        fdout = open(tmpname, O_WRONLY|O_CREAT|O_TRUNC, 0600);
        if (fdout == -1) {
            g_error("Cannot open tmp file for write: %s", strerror(errno));
            close(fd);
            g_free(tmpname);
            return -1;
        }

        for (i=0;i<count;i++) {
            info = camel_mbox_summary_index(s, i);
            g_assert(info);
            g_assert(info->info.content);

            content = (CamelMboxMessageContentInfo *)info->info.content;

            /* FIXME: Must also write out xev headers etc, as appropriate? */

            /* we need to use the end of the previous message, becuase the beginning of
               this message doesn't include the "^From " line. */

            /* do we remove this message? */
            if (info->info.flags & CAMEL_MESSAGE_DELETED) {
                printf("Deleting message: %s\n", info->info.uid);
                camel_mbox_summary_copy_block(fd, fdout, last_write, last_start-last_write);
                offset += (content->endpos - last_start);
                last_write = content->endpos;
                last_start = last_write;

                /* remove this message from the index */
                if (s->index) {
                    ibex_unindex(s->index, info->info.uid);
                }

                camel_mbox_summary_remove_uid(s, info->info.uid);
                i--; /* redo this index */
                count--;
            } else {
                printf("Keeping message: %s\n", info->info.uid);
                last_start = content->endpos;
                offset_content(content, offset);
                summary_end = content->endpos;
            }
        }
        /* copy the rest of the file ... */
        camel_mbox_summary_copy_block(fd, fdout, last_write, INT_MAX);

        close(fd);
        if (close(fdout) == -1) {
            g_error("Cannot close tmp folder: %s", strerror(errno));
            unlink(tmpname);
            g_free(tmpname);
            return -1;
        }

        if (rename(tmpname, s->folder_path) == -1) {
            g_error("Cannot rename folder: %s", strerror(errno));
            unlink(tmpname);
            g_free(tmpname);
            return -1;
        }

        /* force an index sync */
        if (s->index) {
            ibex_write(s->index);
        }

        /* update summary size to match the actual (written) folder size ... */
        s->size = summary_end;
        /* and the time to match the newly written time, so we dont update needlessly */
        if (stat(s->folder_path, &st) == 0) {
            s->time = st.st_mtime;
        }

        camel_mbox_summary_save(s);
    }

    return 0;
}


#if 0
int main(int argc, char **argv)
{
    if (argc<2) {
        printf("usage: %s mbox\n", argv[0]);
        return 1;
    }

    gtk_init(&argc, &argv);

    index_folder(argv[1]);

    return 0;
}
#endif